Molecular and crystal structure of the regenerated form of (1→3)-α-d-glucan

Carbohydrate-protein interactions

“…Several X-ray and conformational studies have been reported on homopolymers of 1→2, 1→3 and 1→4 glucose and 1→4 mannose. [101,121,122,133,154,4,109] In order to validate our simulation methodology we have computed torsional angles as a function of time for these sugars and found that both the minimum energy configurations as well as fluctuations are consistent with previously reported values [101,121,122,133,154,4,109].…”

“…The choice of the initial conformations was based on previous experimental information. [101,121,122,133,154,4,109]. We used the GLYCAM [77] force field for all our calculations.…”

Microbial Polysaccharide Products

“…This alteration in properties was ascribed to the formation of a pseudocrystalline form with greatly reduced hydration of the curdlan following high temperature treatment (Kanzawa et al, 1989 yielded a single helical structure in which there was one molecule of water per glucose residue (Okuyama et al, 1996). Although it has been less studied than curdlan, the linear l,3-Cl-D-glucan mutan produced by Streptococcus mutans also exhibits crystalline structure (Ogawa et al, 1981) Gellan has proved to be one of the most interesting recent microbial polysaccharide introductions. It is produced commercially from a strain of Sphillgomonas elodea and has a linear tetrasaccharide repeat unit (Jansson et ai., 1986).…”

Conformation of (1→3)-α-D-Glucan Tribenzoate

“…The initial atomic coordinates for the asymmetric unit (o-glucose residue) were from those of o-glucose in the crystal of (l ~ 3)-a-o-glucan. 5) The restriction of the glycosidic bond angle for the a-l,3-linkage was given between 105 and 125°. The distance between the reducing and non-reducing ends was fixed at 19.63 A, which was the fiber repeat observed in the X-ray pattern.…”

“…(1-+3)-et-o-Glucan triacetate shows much higher resolution ability for trans-stilbene oxide than cellulose triacetate II (CTA II); while the tribenzoate derivative of cellulose (TBC) also shows distinct resolution ability. 2,3) Both (1-+4)-fJ-o-glucan (cellulose)4) and (1-+3)-et-oglucan 5 ) take nearly a fully extended two-fold helical conformation, although their h values (the advance per residue along the helix axis) are different from each other: 5.15 A for the former and 4.22 A for the latter. No drastic change in the backbone conformation of cellulose has been observed when it was acetylated.…”